Recently, such electrostatic recording apparatuses as an electro-photo copier, a laser printer and the like have been made more and more compacts and propagation of personal use of such electrostatic recording apparatuses requiers higher reliability in respect of the quality. In an electrostatic recording apparatus, a toner image formed on a photosensitive member in the course of the electrostatic photography process is transferred to a transfer paper which is then thermally fixed to bear a record. After the transfer process, the toner left on the photo-sensitive member is removed by means of a cleaning blade or a cleaning roller and recovered and stored in a waste toner container.
In a recording apparatus of a compact type, the image forming system mainly consisting of a photo-sensitive member and a thermally fixing apparatus are disposed quite closely to each other. With regard to the material for the respective apparatuses, plastic molded members are frequently utilized in view of reduced cost, light weight and so forth. Furthermore, a consideration has been taken to enable the photo-sensitive member unit including the cleaning apparatus and the developing apparatus to be accomodated in one image forming case which is in turn removed from or attached to the recording apparatus as a unit to make it easy for a user to exchange the unit. It is to be noted, however, that the fixing temperature at the thermally fixing apparatus can not be considerably lowered exceptionally even if the apparatus in question has been made compact due to limitation in fixing characteristics or at most down to the range of 160.degree. C. and 170.degree. C. Naturally those units disposed in proximity to the fixing apparatus will be subjected to the effect by heat. In particular, the waste toner container for the cleaning apparatus has to be located rather near to the fixing apparatus in view of the layout, and the toner in such a waste toner container will get solidified in the form of cake if the temperature goes up abnormally or the so-called caking will be resulted. Consequently, the level detector adapted to detect the level of the surface of toner material in the container will fail in satisfactory operation. As a result, the toner packing generated in the container will cause the toner to overflow from the clearance between the toner cleaning member and the photo-sensitive member, resulting in poor cleaning, deterioration inside the electrostatic recording apparatus, damage to the driving gears and the like problems.